Fire extinguishing method and apparatus

ABSTRACT

Fire extinguishing method, especially for spaces intended for the storage of aircraft, such as hangars, in which method a fire extinguishing medium, especially a liquid mist, is sprayed via at least one first nozzle ( 2 ) in the area, seen in a vertical direction, between an object ( 1 ) to be protected/extinguished, such as an aircraft, and the floor ( 3 ) or equivalent af the storage space. At least one first nozzle ( 2 ) is arranged to spray mainly in the area between the object ( 1 ) to be extinguished, such as an aircraft, and the floor ( 3 ) of the storage space or equivalent at least in a horizontal plane mainly in one first direction.

BACKGROUND OF THE INVENTION

The present invention relates to a fire extinguishing method as definedin the preamble of claim 1, especially for spaces intended for thestorage, maintenance, testing etc. of aircraft, such as hangars, inwhich method a fire extinguishing medium, especially a liquid mist, issprayed, via at least one first nozzle in an area, seen in a verticaldirection, between an object to be protected/extinguished, such as anaircraft, and the floor of the space or equivalent.

The invention also relates to a fire extinguishing apparatus as definedin the preamble of claim 12, especially for spaces intended for thestorage, maintenance, testing etc. of aircraft, such as hangars, saidapparatus comprising at least one first nozzle, which, when activated,is directed to spray an extinguishing medium, especially a liquid mist,in the area, seen in a vertical direction, between an object to beprotected/extinguished, such as an aircraft, and the floor of thestorage space, and means for supplying an extinguishing medium to theaforesaid nozzles.

Fire extinguishing systems of spaces, such as various hangars, intendedfor the storage, maintenance, testing etc. of aircraft, such asairplanes, are very important as a means of protecting the valuablecraft from a possible fire. Fires particularly difficult to extinguishare those occurring e.g. under an airplane, especially under its wing.So far, fire extinguishing systems used in hangars typically comprisenozzles installed above the object and/or in the floor, through which issprayed a fire extinguishing medium, especially extinguishing foam. Insuch systems, the aim is to fill the entire space between the aircraftand the floor with foam. At the same time, however, efforts are made toprevent adverse effects of the foam on the aircraft. A disadvantage withsystems using extinguishing foam is especially the cleaning workrequired after their application, especially on aircraft. Moreover, toallow such a system to be used, the space in which extinguishing foam isto be applied has to be evacuated before the system is triggered intoaction, which thus introduces a delay between the detection of fire andactivation of the extinguishing system. Fire extinguishing systems usingso-called film-forming foam are also known. In these systems, theextinguishing medium forms a film on the surface of objects. One of thedisadvantages of these is that they typically have highly corrosiveproperties, which may damage the object to be protected. Moreover, theireffectiveness is limited to only given types of fire. In addition,prior-art fire extinguishing systems are difficult to provide in thespaces to be protected without said systems interfering with otheractivities carried on in them.

In fire-fighting technology, extinguishing systems based on water mistare also known, the use of which typically does not involve thedisadvantages of systems using extinguishing foam.

BRIEF DESCRIPTION OF THE INVENTION

The object of the present invention is to achieve a solution that uses aliquid mist, especially water mist as an extinguishing medium forextinguishing fires in storage spaces for aircraft, such as airplanes.Another object of the invention is to achieve an effective extinguishingsolution that can be used to put out fires occurring under an object tobe protected, such as an aircraft.

The method of the invention is mainly characterized in that at least onefirst nozzle is arranged to spray mainly in the area between the objectto be extinguished, such as an aircraft, and the floor of the storagespace at least in a horizontal plane mainly in one first direction.

The method of the invention is additionally characterized by what ispresented in claims 2-11.

The apparatus of the invention is characterized in that at least onefirst nozzle has been arranged to spray mainly in the area between theobject to be extinguished, such as an aircraft, and the floor of thestorage space at least in a horizontal plane mainly in one firstdirection.

The apparatus of the invention is additionally characterized by what ispresented in claims 13-22.

The solution of the invention has many significant advantages. Accordingto the invention, the nozzles spraying between the object to beprotected and the floor are very effective in subduing the flames of afire between the object and the floor at an early stage, protecting thebottom of the object even alone. Sprays directed in the same directionboost the effect of each other, with the result that their penetrationis increased, among other things. In addition, the mist of extinguishingmedium sprayed from nozzles placed above the object to be protected isdirected, due to the currents generated, to the area between the objectand the floor. The solution of the invention keeps the mist ofextinguishing medium very well within the area to be protected, even inis open spaces. The method and apparatus of the invention are very wellapplicable for fire protection of different aircraft storage spaces. Byusing the solution of the invention, different types of liquid fires,such as fires in reservoirs or flowing fires of flammable liquids. Inthe case of such fires, the seat of fire is typically below the objectto be protected. The solution of the invention is also well applicablefor fire protection of buildings where the distance from the floor tonozzles mounted overhead, e.g. in the ceiling, is relatively large, e.g.5-10 m. Thus, the solution of the invention can be easily installed inspaces to be protected without interfering with other activities.

BRIEF DESCRIPTION OF ILLUSTRATIONS

In the following, the invention will be described in detail by the aidof an example with reference to the attached drawings, wherein

FIG. 1 presents a diagram of an apparatus according to the invention inside view,

FIG. 2 presents an arrangement according to the invention as seen fromdirection II-II in FIG. 1, and

FIG. 3 shows the position of the nozzles in a solution according to theinvention, projected onto a horizontal plane.

DETAILED DESCRIPTION OF THE INVENTION

The figures present diagrams representing a fire extinguishingarrangement according to the invention. The arrangement of the inventionis designed for fire protection of and extinguishing of fires in spacesintended especially for the storage of aircraft, such as hangars. In thefigure, the object 1 to be extinguished, such as an aircraft, is shownin a simplified diagrammatic form. A first nozzle intended for sprayingan extinguishing medium is indicated in the figures by reference number2 and the corresponding spray by reference number 2′. The spray headused to spray the extinguishing medium, which may comprise a pluralityof nozzles 2, 4, is not provided with a separate number, but the numberrepresenting the nozzle also represents a possible spray head. The fireextinguishing system typically comprises at least one first nozzle 2,typically, but not necessarily at least one second nozzle 4 and meansfor supplying an extinguishing medium to the nozzles 2, 4. The means forsupplying an extinguishing medium to the nozzles typically comprise anoperating unit 6 and a piping system 5 connecting it to the nozzles 2,4. The system also comprises a fire detector 7, which is connected tothe operating unit, the fire extinguishing system being activated on thebasis of the signal obtained from the fire detector. It is obvious thatthe system can be activated in other ways, too, or it can be activatedmanually. The system may also comprise several operating units 6, andtheir operation may be independent of each other. Thus, the firstnozzles 2 spraying towards the floor may function independently of thesecond nozzles 4 spraying from above. Therefore, the extinguishingmediums used in the systems may differ from each other. It is thusthinkable that the first nozzles 2 could spray e.g. an at leastpartially foam-based extinguishing medium while the second nozzles 4spray a liquid mist.

The nozzles 2, 4 are designed for spraying an extinguishing medium, suchas a liquid mist, especially water mist. The fire extinguishingapparatus, especially for spaces intended for the storage of aircraft,such as hangars, comprises at least one first nozzle 2, which, whenactivated, is directed to spray an extinguishing medium, especiallyliquid mist, in the area between the object 1 to be extinguished, suchas an aircraft, and the floor 3 of the storage space, seen in a verticaldirection, and at least one second nozzle 4 above the object to beextinguished, such as an aircraft, and means for supplying anextinguishing medium to said nozzles 2, 4. The first nozzle 2 has beenarranged to spray mainly in the area (or the volume) between the target1 to be extinguished, such as an aircraft, and the floor 3 of thestorage space at least in a horizontal plane mainly in one firstdirection. The first nozzle is arranged to spray the majority of itsspray into the area between the object and the floor and with a mainlyhorizontal vector. At least one other first nozzle 2 has been arrangedto spray, when activated, an extinguishing medium at a distance from onefirst nozzle 2 at least in a horizontal plane mainly in one firstdirection so that the sprays 2′ from the first nozzles 2 boost eachother. The nozzles 2, 4 are so disposed relative to each other that, dueto the action of the suction created by the spray 2′ from at least onefirst nozzle 2, at least part of the extinguishing medium sprayed by atleast one second nozzle 4 is directed into the space between the object1 to be extinguished, such as the fuselage of an aircraft, and the floor3. The arrows in FIG. 1 are intended to roughly indicate thecircumstance that at least part of the extinguishing medium is directedfrom above the object 1 into the space below it.

The nozzles 2, 4 are so arranged relative to each other that a pluralityof first nozzles 2, when activated, spray an extinguishing medium mainlyin one first direction while a plurality of second nozzles 4 spray in atleast one second direction, so that the currents generated by the spraysserve to keep the mist of extinguishing medium mainly within the desiredarea. The second direction is typically different from the firstdirection. The spray 2′ from at least one first nozzle 2 is directed ina horizontal plane mainly in the direction of the longitudinal axis ofthe aircraft or an axis parallel to it. At least some of the secondnozzles 4 are directed to spray the upper part of the object 1 to beprotected, such as an aircraft, preferably in a substantially radialdirection towards the assumed longitudinal axis of the object. At leastsome of the first nozzles 2 are disposed one after the other in thedirection of the longitudinal axis of the object to be protected and/orside by side at a distance from each other in a direction transverse tothe longitudinal axis. At least part of the spray 2′ from at least onefirst nozzle 2 is directed towards the lower part of the object 1 to beprotected, such as the bottom of an aircraft. At least one spray 2′ fromat least one first nozzle 2 is directed obliquely upwards in a verticalplane. A plurality of first nozzles are arranged to spray anextinguishing medium into the area 10 between the floor 3 and the object1, such as an aircraft, so that the sprays cover a substantial part ofthe lower surface of the object 1. In the embodiment illustrated in thefigures, the first nozzles 2 are directed in a horizontal plane mainlyin the direction of the longitudinal axis of the object 1 to beprotected. However, it is obvious that they can be directed as requiredin each embodiment.

The first nozzles/spray heads 2 are typically disposed in the floor 3.The nozzles/spray heads 2 are preferably so arranged that, whenactivated, they spring upwards from the level of the floor 3, e.g. asdescribed in specification WO93/00962. When a liquid mist, especiallywater mist is used as an extinguishing medium, the nozzles 2 arepreferably of the type described in specification WO01/45799. The secondnozzles/spray heads 4 are preferably of the type described inspecification WO92/20453.

The operating unit may be e.g. a constant-pressure pump. The pressure inthe piping is typically over 30 bar, preferably over 50 bar, mostpreferably over 70 bar. The liquid mist produced by the nozzles istypically very fine. The droplet size (D_(v90)) is typically below 400micrometers, preferably below 300 micrometers, most preferably below 200micrometers.

in the arrangements according to the invention, the distance of thesecond nozzles 4 placed above the object from the floor level 3 isrelatively large, e.g. 5-10 meters. The distance between the firstnozzles/spray heads 2 may vary depending on application. In a typicalcase, the distance is 1-5 m, preferably 2-4 m, most preferably about 3meters. The distance between the second nozzles/spray heads 4 may varyaccording to application. In a typical case, the distance is 2-6 m,preferably about 3-5 m, most preferably about 4 m. in the method of theinvention, when the system is activated, e.g. in consequence of a fireunder the object to be protected, the first nozzles/spray heads 2 startspraying a mist of extinguishing medium in a set direction. The nozzles2 have been so directed that the sprays 2′ from the nozzles/spray headsboost each other, and therefore a very effective impact can be exertedon the flames in the seat of fire. At the same time, a mist ofextinguishing medium is also sprayed from the nozzles/spray heads 4disposed above the object 1 to be protected. Due to the suctiongenerated by the first nozzles 2, currents are formed in he protectedarea of the object so that the mist of extinguishing medium sprayed fromthe second nozzles 4 is directed into the area between the object andthe floor. Extinguishing medium is sprayed by a plurality of firstnozzles 2 mainly in one first direction and by a plurality of secondnozzles 4 in at least one second direction, the mist of extinguishingmedium being kept within the desired area by the currents thus formed.The spray 2′ from at least one first nozzle 2 is directed at least in ahorizontal plane mainly in the direction of the longitudinal axis of theaircraft or an axis parallel to it. At least some of the second nozzles4 are directed to spray substantially towards the upper part of theobject 1 to be protected, such as an aircraft, preferably substantiallyin a radial direction towards the assumed longitudinal axis of theobject 1 to be protected. Extinguishing medium is sprayed from aplurality of first nozzles 2, at least some of which have been arrangedone after the other in the direction of the longitudinal axis of theobject 1 to be protected and/or side by side at a distance from eachother in at least one direction transverse to the longitudinal axis. Atleast part of the spray 2′ from at least one first nozzle 2 is directedto spray towards the lower part 1 of the object to be protected, such asthe bottom of an aircraft. Part of at least one spray 2′ from at leastone first nozzle 2 is directed to spray obliquely upwards in a verticalplane. A plurality of first nozzles 2 are arranged to spray anextinguishing medium into the area between the floor 3 and the object 1,such as an aircraft, so that the sprays cover a substantial part of thelower surface of the object 1.

It is obvious to the person skilled in the art that the invention is notlimited to the embodiments described above, but that it may be variedwithin the scope of the following claims.

1. Fire extinguishing method, especially for spaces intended for thestorage of aircraft, such as hangars, in which method a direextinguishing medium, especially a liquid mist, is sprayed via at leastone first nozzle (2) in an area between an object (1) to beprotected/extinguished, such as an aircraft, and a floor (30 orequivalent of the space, characterized in that at least one first nozzle(20 is arranged to spray mainly in the area between the object (1) to beextinguished, such as an aircraft, and the floor (3) of the storagespace or equivalent at least in a horizontal plane mainly in one firstdirection.
 2. Method according to claim 1, characterized in that atleast one other first nozzle (2) is arranged to spray an extinguishingmedium at a distance form one first nozzle (2) at least in a horizontalplane substantially in one first direction so that the sprays (2′) fromsaid first nozzles (2) boost each other.
 3. Method according to claim 1,characterized in that a fire extinguishing medium, especially liquidmist, is sprayed via at least one second nozzle (40 from above theobject to be extinguished, such as an aircraft.
 4. Method according toclaim 1, characterized in that, due to the action of the suctionproduced by the spray (2′) form at least one first nozzle (2) at leastpart of the mist of extinguishing medium sprayed by at least one secondnozzle (4) is directed into the space between the object (1) to beextinguished, such as an aircraft, and the floor (3).
 5. Methodaccording to claim 1, characterized in that, in the method,extinguishing medium is sprayed via a plurality of first nozzles (2)mainly in one first direction and via a plurality of second nozzles (4)in at least one second direction, the mist of extinguishing medium beingkept mainly within the desired area by the currents thus formed. 6.Method according to claim 1, characterized in that the spray (2′) fromat least one firs nozzle (2) is directed, at least in a horizontalplane, mainly in the direction of the longitudinal axis of the object,such as the aircraft, or an axis parallel to it.
 7. Method according toclaim 1, characterized in that at least some of the second nozzles (4)are directed to spray substantially towards the upper part of the object(1) to be protected, such as an aircraft.
 8. Method according to claim1, characterized in that extinguishing medium is sprayed from aplurality of first nozzles (2), at least some of which have beenarranged one after the other in the direction of the longitudinal axisof the object (1) to be protected and/or side by side at a distance fromeach other in at least one direction transverse to the longitudinalaxis.
 9. Method according to claim 1, characterized in that at leastpart of the spray (2′) form at lest one first nozzle (2) is directedtowards the lower part of the object (1) to be protected, such as thebottom of an aircraft.
 10. Method according to claim 1, characterized inthat at least one spray (2′) from at least one first nozzle (2) isdirected obliquely upwards in a vertical plane.
 11. Method according toclaim 1, characterized in that a plurality of first nozzles (2) arearranged to spray an extinguishing medium into the area between thefloor (3) and the object (1), such as an aircraft, so that the sprayscover a substantial part of the lower surface of the object (1). 12.Fire extinguishing apparatus, especially for spaces intended for thestorage of aircraft, such as hangars, said apparatus comprising at leastone first nozzle (2), which is so directed that, in a activated state,it will spray a fire extinguishing medium, especially a liquid mist, inthe area, seen in a vertical direction, between an object (1) to beprotected/extinguished, such as an aircraft, and the floor (3) of thestorage space or equivalent, and means for (5, 6) for supplying anextinguishing medium to said nozzles (2, 4), characterized in that atleast one first nozzle (2) is arranged to spray mainly in the areabetween the object (1) to be extinguished, such as an aircraft, and thefloor (3) of the storage space at least in a horizontal plane mainly inone first direction.
 13. Apparatus according to claim 12, characterizedin that at least one other first nozzle (2) has been arranged to sprayan extinguishing medium at a distance from one first nozzle (2) at leastin a horizontal plane substantially in one first direction so that thesprays (2′) from said first nozzles (2) boost each other.
 14. Apparatusaccording to claim 12, characterized in that apparatus comprising atleast one second nozzle (4), which is so directed that, in activatedstate, it will spray a fire extinguishing medium, especially liquidmist, above the object (1) to be protected/extinguished, such as anaircraft, and means (5, 6) for supplying an extinguishing medium to saidnozzle (4).
 15. Apparatus according to claim 12, characterized in thatthe nozzles (2, 4) are so arranged relative to each other that, due tothe action of the suction produced by the spray (2′) from at least onefirst nozzle (2), at least part of the mist of extinguishing mediumsprayed by at least one second nozzle (4) is directed into the spacebetween the object (10 to be extinguished, such as the fuselage of anaircraft, and the floor (3).
 16. Apparatus according to claim 12,characterized in that the nozzles (2, 4) are so arranged relative toeach other that a plurality of first nozzles (2), when activated, willspray an extinguishing medium mainly in one first direction and aplurality of second nozzles (4) spray in at least one second directionso that the mist of extinguishing medium is kept mainly within thedesired area by the currents produced by the sprays.
 17. Apparatusaccording to claim 12, characterized in that the spray (2′) from atleast one first nozzle (2) is directed in a horizontal plane mainly inthe direction of the longitudinal axis of the aircraft or an axisparallel to it.
 18. Apparatus according to claim 12, characterized inthat at least some of the second nozzles (4) are directed to spraysubstantially towards the upper part of the object (1) to be protected,such as an aircraft, preferably substantially in a radial directiontowards the assumed longitudinal axis of the object (1).
 19. Apparatusaccording to claim 12, characterized at least some of the first nozzles(2) are arranged one after the other in the direction of thelongitudinal axis of the object and/or side by side at a distance fromeach other in a direction transverse to the longitudinal axis. 20.Method according to claim 12, characterized in that at least part of thespray (2′0 from at least one first nozzle (2) is directed towards thelower part of the object (1) to be protected, such as the bottom of anaircraft.
 21. Method according to claim 12, characterized in that atleast one spray (2′) from at least one first nozzle (2) is directedobliquely upwards in a vertical plane.
 22. Method according to claim 12,characterized in that a plurality of first nozzles (2) are arranged tospray an extinguishing medium into the area between the floor (3) andthe object (1), such as an aircraft, so that the sprays cover asubstantial part of the lower surface f the object (1).